Discrepency in Hobbit Birthday Customs

Hey, it's been a while!!! But I'm rereading FOTR and discovered an interesting something in regards to birthday customs of Hobbits that could probably be stretched to some sort of discussion and theories:

The Hobbits give other Hobbits presents on their birthdays. Yet when Smeagol claims the Ring is his birthday present for his birthday, and Deagol states he already gave him a birthday present, it would seem the river Hobbits follow a different custom. They recieve birthday presents on their birthdays.

So where did this difference arise? Why would it arise? Is there something about the river culture that would make these Hobbits develop this custom differently from those in the Shire? I'd be interested to hear others takes on this.

Sorry, I get a little too excited sometimes. You probably don't remember me since I'm just a crazy and secretive little Hobbit, but I remember you and I am so glad that you are back.

This is one of the wonderful subjects on which we have the word of Tolkien himself. Someone asked him about this and he wrote a letter which was of course published in Humphrey Carpenter's book.

We all know that Hobbits can be very private people at times. Birthdays are and aren't one of those times. Hobbits give away presents at their parties, but their family and close friends will give them presents, usually early in the day before all the hustle and bustle, and these are generally more useful things and of some personal import; they are therefore considered to be none of anyone else's business. Doing it thus for one thing avoids the terrible embarrassment otherwise incurred if someone should bring the same gift as another someone. It is of course this kind of present that Gollum was refering to. I think Tolkien might also have said that the custom of giving others presents might not have evolved at the time/place Smeagol had that birthday since it is rather an expensive one, and his being a smaller river-side community it might have been prohibitively costly even if they had thought of it, which seems perhaps unlikely. The Shire being a much richer and more advanced society they had public celebrations at which to give things away, but the custom of giving the birthday-person gifts was in fact the much older and probably more important tradition.

Darn. I think I got all that right. Does anyone actually have the Letters? Could you perhaps post that one letter here? I don't actually own a copy or I would, it would make everything so much clearer...

Receiving of gifts: this was an ancient ritual connected with kinship. It was in origin a recognition of the byrding's membership of a family or clan, and a commemoration of his formal 'incorporation'. No present was given by father or mother to their children on their (the children's) birthdays (except in the rare cases of adoption); but the reputed head of the family was supposed to give something, if only in 'token'.
Giving gifts: was a personal matter, not limited to kinship. It was a form of 'thanksgiving', and taken as a recognition of services, benefits, and friendship shown, especially in the past year.
A trace of this can be seen in the account of Sméagol and Déagol – modified by the individual characters of these rather miserable specimens. Déagol, evidently a relative (as no doubt all the members of the small community were), had already given his customary present to Sméagol, although they probably set out on their expedition v. early in the morning. Being a mean little soul he grudged it. Sméagol, being meaner and greedier, tried to use the 'birthday' as an excuse for an act of tyranny Because I wants it' was his frank statement of his chief claim. But he also implied that D's gift was a poor and insufficient token: hence D's retort that on the contrary it was more than he could afford.